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Precision Medicine and engineering 2024年第2期1卷

作者： Yongcan Li Fangfang Cao Lie Ma Lulu Jin MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 PR China Departments of Diagnostic Radiology Surgery Chemical and Biomolecular Engineering and Biomedical Engineering Yong Loo Lin School of Medicine and College of Design and Engineering National University of Singapore 119074 Singapore Nanomedicine Translational Research Program NUS Center for Nanomedicine Yong Loo Lin School of Medicine National University of Singapore 117597 Singapore

As one of the most abundant biological populations endowed with unique properties such as specific targeting and genetic engineering vectors, bacteria with immunogenic potential have garnered significant attention for their ability to elicit immune activation against tumors. This approach has achieved substantial breakthroughs as a modality for cancer treatment and is known as bacterial immunotherapy. However, the immunosuppressive tumor microenvironment (TME) can inhibit the immune response induced by bacteria and promote tumor growth and metastasis. To overcome this challenge, recent advancements in bacteria-based bioactive materials, which are biological substances synthesized by bacteria, have not only harnessed the inherent properties of bacteria but also specifically targeted the modulation of the TME, providing a more favorable environment for immune activation and significantly enhancing the efficacy of immunotherapy for cancer treatment. This review introduces the key mechanisms of bacteria-based biomaterials as anticancer agents and reviews the latest research progress, along with their clinical applications in cancer treatment. Finally, the potential and challenges of bacteria-based biomaterials for tumor therapy are explored, aiming to provide insights into the functions of bacteria-based bioactive materials and their role in advancing cancer immunotherapy while offering recommendations for the development of new bacteria-based biomaterials.

关键词： Tumor immunotherapy Immune cells Tumor microenvironment Bioactive materials

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Precise Supramolecular Nanoarchitectonics for Simultaneous Enhanced Photoluminescence and Photocatalysis in a Co-Assembly by a Biomimetic Isolation-Conduction Strategy

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Angewandte Chemie 2024年第12期137卷

作者： Dr. Zhao Gao Jianxiang Sun Lulu Shi Wei Yuan Prof. Hongxia Yan Prof. Wei Tian Shaanxi Key Laboratory of Macromolecular Science and Technology Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions School of Chemistry and Chemical Engineering Northwestern Polytechnical University Xi'an 710072 P. R. China Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore

Limited by the two mutually exclusive physicochemical processes of separation and recombination of photogenerated carriers, achieving photoluminescence and photocatalysis simultaneously is extremely challenging but essential for ever-growing complex issues and specialized scenarios. Here we proposed a biomimetic isolation-conduction strategy induced by an arene-perfluoroarene (A−P) interaction for enabling photoluminescence and photocatalytic hydrogen evolution reaction (HER) activity in the co-assembly of aromatic monomers and octafluoronapthalene ( OFN ). Inspired by the isolation-conduction effect of periodic isolation of myelin sheaths on the axons of vertebrate nerve fibers by node of Ranvier, we use OFN as a molecular isolator embedded in the aromatic monomers array to block the singlet-to-triplet pathway, while the enlarged intermolecular dipoles resulting from the A−P interactions facilitate the conduction of photogenerated carriers in the isolated regions. The resultant co-assembly exhibits an enhanced monomeric green emission compared to the corresponding monocomponent self-assembly with weak red emission. Meanwhile, it also has an enhanced photocatalytic HER performance with a rate of 2.45 mmol g −1 h −1 , which is 15.2 times more than the self-assembled one. On this basis, a sequential fluoric wastewater reuse system that includes real-time fluorescence detection/removal of perfluorooctanoic acids and photocatalytic HER device is constructed.

关键词： Self-assembly Arene-Perfluoroarene Interactions Molecular Recognition Photocatalysis Perfluoroalkyl Compounds

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On sparse identification of complex dynamical systems: a study on discovering influential reactions in chemical reaction networks

arXiv

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arXiv 2020年

作者： Harirchi, Farshad Kim, Doohyun Khalil, Omar Liu, Sijia Elvati, Paolo Baranwal, Mayank Hero, Alfred Violi, Angela Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109–2125 United States Department of Mechanical Engineering University of Michigan Ann ArborMI48109–2125 United States Departments of Chemical Engineering Biomedical Engineering Macromolecular Science and Engineering Biophysics Program University of Michigan Ann ArborMI48109–2125 United States

A wide variety of real life complex networks are prohibitively large for modeling, analysis and control. Understanding the structure and dynamics of such networks entails creating a smaller representative network that preserves its relevant topological and dynamical properties. While modern machine learning methods have enabled identification of governing laws for complex dynamical systems, their inability to produce white-box models with sufficient physical interpretation renders such methods undesirable to domain experts. In this paper, we introduce a hybrid black-box, white-box approach for the sparse identification of the governing laws for complex, highly coupled dynamical systems with particular emphasis on finding the influential reactions in chemical reaction networks for combustion applications, using a data-driven sparse-learning technique. The proposed approach identifies a set of influential reactions using species concentrations and reaction rates, with minimal computational cost without requiring additional data or simulations. The new approach is applied to analyze the combustion chemistry of H2 and C3H8 in a constant-volume homogeneous reactor. The influential reactions determined by the sparse-learning method are consistent with the current kinetics knowledge of chemical mechanisms. Additionally, we show that a reduced version of the parent mechanism can be generated as a combination of the significantly reduced influential reactions identified at different times and conditions and that for both H2 and C3H8 fuel, the reduced mechanisms perform closely to the parent mechanisms as a function of the ignition delay time over a wide range of conditions. Our results demonstrate the potential of the sparse-learning approach as an effective and efficient tool for dynamical system analysis and reduction. The uniqueness of this approach as applied to combustion systems lies in the ability to identify influential reactions in specified conditions and times dur

关键词： Learning systems

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Hybrid Vesicles Enable Mechano-Responsive Hydrogel Degradation

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Angewandte Chemie 2023年第41期135卷

作者： Sung-Won Hwang Chung-Man Lim Prof. Cong Truc Huynh Hossein Moghimianavval Prof. Nicholas A. Kotov Prof. Eben Alsberg Prof. Allen P. Liu Department of Chemical Engineering University of Michigan Ann Arbor MI 48109 USA Department of Materials Science and Engineering University of Michigan Ann Arbor MI 48109 USA Department of Biomedical Engineering University of Illinois Chicago Chicago IL 60612 USA Department of Mechanical Engineering University of Michigan Ann Arbor MI 48109 USA Departments of Biomedical Engineering Macromolecular Science and Engineering Biointerfaces Institute University of Michigan Ann Arbor MI 48109 USA Departments of Orthopedic Surgery Pharmacology and Regenerative Medicine and Mechanical and Industrial Engineering University of Illinois Chicago Chicago IL 60612 USA Departments of Biomedical Engineering Biophysics Cellular and Molecular Biology Program Applied Physics Program University of Michigan Ann Arbor MI 48109 USA

Stimuli-responsive hydrogels are intriguing biomimetic materials. Previous efforts to develop mechano-responsive hydrogels have mostly relied on chemical modifications of the hydrogel structures. Here, we present a simple, generalizable strategy that confers mechano-responsive behavior on hydrogels. Our approach involves embedding hybrid vesicles, composed of phospholipids and amphiphilic block copolymers, within the hydrogel matrix to act as signal transducers. Under mechanical stress, these vesicles undergo deformation and rupture, releasing encapsulated compounds that can control the hydrogel network. To demonstrate this concept, we embedded vesicles containing ethylene glycol tetraacetic acid (EGTA), a calcium chelator, into a calcium-crosslinked alginate hydrogel. When compressed, the released EGTA sequesters calcium ions and degrades the hydrogel. This study provides a novel method for engineering mechano-responsive hydrogels that may be useful in various biomedical applications.

关键词： Block Copolymers Functional material Stimuli-Responsive Hydrogel Stress-Induced Degradation Vesicles

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Coconut waste to green nanomaterial: Large scale synthesis of N-doped graphene nano sheets

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Nano-Structures and Nano-Objects 2023年 36卷

作者： Siburian, Rikson Tang, Liang Wei Alias, Yatimah Tok, Alfred Iing Yoong Goei, Ronn Simanjuntak, Crystina Tarigan, Kerista Paiman, Suriati Goh, Boon Tong Anshori, Isa Kurniawan, Cepi Postgraduate Program Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Sumatera Utara Medan 20155 Indonesia Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Sumatera Utara Medan 20155 Indonesia Carbon and Frankincense Research Center Universitas Sumatera Utara Medan 20155 Indonesia Department of Chemistry Faculty of Science Universiti Malaya Kuala Lumpur 50603 Malaysia University Malaya Centre for Ionic Liquids (UMCiL) Universiti Malaya Kuala Lumpur 50603 Malaysia School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore Department of Physics Faculty of Mathematics and Natural Sciences Universitas Sumatera Utara Medan 20155 Indonesia Physics Department Faculty of Science Universiti Putra Malaysia Selangor (Serdang) Seri Kembangan 43400 Malaysia Low Dimensional Materials Research Centre Department of Physics Faculty of Science University of Malaya Kuala Lumpur 50603 Malaysia Biomedical Engineering Department School of Electrical Engineering and Informatics Bandung Institute of Technology Bandung 40132 Indonesia Research Center of Nanoscience and Nanotechnology Bandung Institute of Technology Bandung 40132 Indonesia Chemistry Department Faculty of Mathematics and Natural Sciences Universitas Negeri Semarang Semarang 50229 Indonesia Functional Material Research Center Universitas Negeri Semarang Semarang 50229 Indonesia

In this paper, a breakthrough was achieved in large-scale production of N-doped Graphene Nano Sheets (N-GNS) using coconut fruits. The main objectives were to produce N-GNS on a large scale and assess its electrical conductivity. The process involved two key steps: first, producing GNS from coconut fruits through pyrolysis, and then generating N-GNS by doping with nitrogen using ammonia solution at room temperature. Various analytical techniques were used to characterize the produced N-GNS, including X-ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Raman spectroscopy, and electrochemical cyclic voltammetry and electrochemical impedance spectroscopy. The XRD data indicated that the C (002) peak of N-GNS shifted to a higher 2θ value (2θ = 24.72°) compared to GNS (2θ = 23.86°), suggesting an incorporation of nitrogen into carbon structure in N-GNS. This was further supported by XPS data, which identified N-pyridine (BE = 402.0 eV) and C-N (BE = 286.8 eV) in N-GNS. TEM images showed that N-GNS had a flat surface, and the distance between graphene layers slightly expanded (0.36 nm) compared to graphene layers (0.34 nm). SEM images and EDX data validated the morphology, resembling honeycomb lattices, with a significant content of N atoms. Raman data successfully identified the D-band and G-band in N-GNS, further validating its production. Most importantly, N-GNS exhibited electrical conductivity, making it a promising candidate for conductive and supporting materials in various applications. The significance of this research extends beyond N-GNS production, opening up new avenues for the sustainable synthesis of valuable nanomaterials from coconut fruit waste, contributing to both graphene technology and environmental conservation. © 2023 Elsevier B.V.

关键词： C-sp2 Electrical conductivity Graphene nano sheets N-graphene nano sheets N-pyridine XPS

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Metallic vs. Semiconducting properties of quasi-one-dimensional tantalum selenide van der Waals nanoribbons

arXiv

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arXiv 2021年

作者： Kargar, Fariborz Krayev, Andrey Wurch, Michelle Ghafouri, Yassamin Debnath, Topojit Wickramaratne, Darshana Salguero, Tina T. Lake, Roger Bartels, Ludwig Balandin, Alexander A. Center Department of Electrical and Computer Engineering University of California RiversideCA92521 United States HORIBA Scientific NovatoCA94949 United States Department of Chemistry and Material Science and Engineering Program University of California RiversideCA92521 United States Department of Chemistry University of Georgia AthensGA30602 United States Laboratory for Terahertz and Terascale Electronics Department of Electrical and Computer Engineering University of California RiversideCA92521 United States Center for Computational Materials Science U.S. Naval Research Laboratory WashingtonDC20375 United States

We conducted a tip-enhanced Raman scattering spectroscopy (TERS) and photoluminescence (PL) study of quasi-1D TaSe3-δ nanoribbons exfoliated onto gold substrates. At a selenium deficiency of δ~0.25 (Se/Ta=2.75,), the nanoribbons exhibit a strong, broad PL peak centered around ~920 nm (1.35 eV), suggesting their semiconducting behavior. Such nanoribbons revealed a strong TERS response under 785-nm laser excitation, allowing for their nanoscale spectroscopic imaging. Nanoribbons with a smaller selenium deficiency (Se/Ta=2.85, δ~0.15) did not show any PL or TERS response. The confocal Raman spectra of these samples agree with the previously-reported spectra of metallic TaSe3. The differences in the optical response of the nanoribbons examined in this study suggest that even small variations in Se content can induce changes in electronic structure, causing samples to exhibit either metallic or semiconducting character. The temperature-dependent electrical measurements of devices fabricated with both types of materials corroborate these observations. The density-functional-theory calculations revealed that incorporation of an oxygen atom in a Se vacancy can result in band gap opening and thus enable the transition from a metal to a semiconductor. However, the predicted bandgap is substantially smaller than that derived from PL data. These results indicate that the properties of van der Waals materials can vary significantly depending on stoichiometry, defect types and concentration, and possibly environmental and substrate effects. In view of this finding, local probing of nanoribbon properties with TERS becomes essential to understanding such low-dimensional systems. Copyright © 2021, The Authors. All rights reserved.

关键词： Van der Waals forces

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Scalable, Durable, and Recyclable Metal‐Free Catalysts for Highly Efficient Conversion of CO2 to Cyclic Carbonates

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Angewandte Chemie 2020年第51期132卷 23491-23498页

作者： Yao‐Yao Zhang Guan‐Wen Yang Rui Xie Li Yang Prof. Bo Li Prof. Dr. Guang‐Peng Wu MOE Laboratory of Macromolecular Synthesis and Functionalization Adsorption and Separation Materials and Technologies of Zhejiang Province Department of Polymer Science and Engineering Zhejiang University Zhe Da Road 38 Hangzhou 310027 China College of Material Chemistry and Chemical Engineering Hangzhou Normal University Yuhangtang Road 2318 Hangzhou 311121 China

A highly active bifunctional organoboron catalyst with the advantages of scalable preparation, thermostability, and recyclability was reported for the cyclization of CO2 and epoxides. An intramolecular cooperative mechanism was substantiated by investigations into the crystal structure of the catalysts, structure–performance relationships, kinetic studies, and the key reaction intermediates.A series of highly active organoboron catalysts for the coupling of CO2 and epoxides with the advantages of scalable preparation, thermostability, and recyclability is reported. The metal‐free catalysts show high reactivity towards a wide scope of cyclic carbonates (14 examples) and can withstand a high temperature up to 150 °C. Compared with the current metal‐free catalytic systems that use mol % catalyst loading, the catalytic capacity of the catalyst described herein can be enhanced by three orders of magnitude (epoxide/cat.=200 000/1, mole ratio) in the presence of a cocatalyst. This feature greatly narrows the gap between metal‐free catalysts and state‐of‐the‐art metallic systems. An intramolecular cooperative mechanism is proposed and certified on the basis of investigations on crystal structures, structure–performance relationships, kinetic studies, and key reaction *** a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the *** note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

关键词： cycloaddition CO2 capture cooperative mechanisms cyclic carbonates metal-free catalysts

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Perovskite superlattices with efficient carrier dynamics

Research Square

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Research Square 2021年

作者： Xu, Sheng Lei, Yusheng Li, Yuheng Lu, Chengchangfeng Yan, Qizhang Gong, Huaxin Zhang, Song Zhou, Jiayun Zhang, Ruiqi Chen, Yimu Tsai, Hsinhan Gu, Yue Hu, Hongjie Lo, Yu-Hwa Nie, Wanyi Lee, Taeyoon Luo, Jian Yang, Kesong Jang, Kyung-In Department of Nanoengineering University of California San Diego La Jolla CA92093-0448 United States Department of Chemical Engineering Stanford University StanfordCA94305 United States Department of Electrical and Computer Engineering University of California San Diego La Jolla CA92093 United States Material Science and Engineering Program University of California San Diego La Jolla CA92093-0418 United States Los Alamos National Laboratory Los AlamosNM87545 United States School of Electrical and Electronic Engineering Yonsei University Seoul03722 Korea Republic of Department of Bio and Brain Engineering Korea Institute of Science and Technology Korea Republic of Department of Robotics Engineering Daegu Gyeongbuk Institute of Science and Technology Daegu42988 Korea Republic of Department of Bioengineering University of California San Diego La Jolla CA92093-0412 United States

Compared with their three-dimensional counterparts, low-dimensional metal halide perovskites with periodic inorganic/organic structures have shown promising stability and hysteresis-free electrical performance, which paves the way for next-generation optoelectronic devices. However, when integrated in devices, they have relatively limited efficiencies because devices usually require carrier transport through the film thickness direction. In conventionally grown single crystals, the carrier transport in the thickness direction is hindered by the insulating organic spacers. In addition, the strong quantum confinement from the organic spacers limits the generation and transport of free carriers. The carrier dynamics is further compromised by the presence of grain boundaries in polycrystals. Here, we report a low-dimensional metal halide perovskite superlattice with efficient carrier transport in three dimensions by epitaxial growth. Epitaxy on a slightly lattice-mismatched substrate compresses the organic spacers in the superlattice, which weakens the quantum confinement and further improves carrier dynamics. The performance of a low-dimensional perovskite superlattice solar cell has been certified under the quasi-steady state for the first time. Moreover, the device shows an unusually high open-circuit voltage, due to a unique intra-band exciton relaxation mechanism. © 2021, CC BY.

关键词： Grain boundaries

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Chiral Phonons in Biocrystals

Research Square

引用

Research Square 2021年

作者： Choi, Won Jin Yano, Keiichi Cha, Minjeong Colombari, Felippe M. Wang, Yichun Lee, Sang Hyun Kruger, John M. de Moura, André F. Kotov, Nicholas A. Department of Materials Science and Engineering University of Michigan Ann ArborMI48109 United States Biointerfaces Institute University of Michigan Ann ArborMI48109 United States Department of Chemical Engineering University of Michigan Ann ArborMI48109 United States SP Campinas13.083-100 Brazil Department of Biomedical Engineering University of Michigan Ann ArborMI48109 United States Department of Chemical and Biochemical Engineering University of Notre Dame South BendIN46556 United States Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109 United States Department of Small Animal Clinical Sciences Michigan State University East LansingMI48824 United States Department of Chemistry Federal University of São Carlos SP São Carlos13565-905 Brazil Program in Macromolecular Science and Engineering University of Michigan Ann ArborMI48109 United States

Chiral phonons are concerted mirror-symmetric movements of atomic groups connected by covalent and intermolecular bonds. Finding chiral phonons in biocrystals is fundamentally and technologically important because these lattice vibrations should be highly specific to their short- and long-range organizations. Based on theoretical and experimental data they might be expected but not identified or utilized. Here we show that terahertz chiroptical spectroscopy enables registration and attribution of chiral phonons in microcrystals of numerous amino acids and dipeptides. Theoretical analysis and computer simulations confirm that sharp mirror-symmetric bands observed for left and right enantiomers originate from collective vibrations of biomolecules interconnected by hydrogen bonds into helical chains. Structure-property relationships for strong phonons with rotatory components in biocrystals were also identified. Bladder stones and health supplements display strong spectral signatures of chiral phonons indicating their immediate importance for biomedicine. © 2021, CC BY.

关键词： Phonons

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Surface-Wave Coupling in Double Floquet Sheets Supporting Phased Temporal Wood Anomalies

arXiv

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arXiv 2022年

作者： Tsai, Ya-Wen Wang, Yao-Ting Galiffi, Emanuele Alù, Andrea Yen, Ta-Jen Department of Material Sciences and Engineering National Tsing Hua University Hsinchu300 Taiwan DepartmentofMathematics ImperialCollege London LondonSW7 2AZ United Kingdom Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Physics Program Graduate Center of the City University of New York New YorkNY10016 United States

We investigate symmetry-selective surface-mode excitation in a general periodically time-modulated double-layer system, where the modulation of the two layers has a constant phase difference. By deriving a semi-analytic transfer matrix formalism of a Drude-dispersive double-layer structure with periodic time-modulation, we calculate the scattering amplitudes and the corresponding transmission coefficient. Our results show that the phase-difference between the modulation of the two sheets plays an essential role in significantly enhancing and selectively exciting either the even or odd surface mode with high efficiency. We verify our calculations with full-wave time-domain simulations, showing that efficient switching between the surface-wave excitation of the two distinct modal channels can be achieved, even under illumination froma single off-resonant Gaussian pulse, by controlling the phase difference between the two modulations. Our results pave the way towards ultrafast, symmetry-selective mode excitation and switching via temporalmodulation. © 2022, CC BY.

关键词： Modulation

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